Bruising

Basics

DESCRIPTION

Bruises are the result of extravasation of blood into the skin. Conventional usage often groups petechiae and bruises (or ecchymoses) together as purpura and defines them as follows:

Petechiae: flat, red, or reddish purple; 1 to 3 mm; nonblanching
Ecchymoses: larger than petechiae, local extravasation, nonpulsatile, sometimes palpable, color depends on age of lesion

EPIDEMIOLOGY

PREVALENCE

<1% nonmobile babies
17% cruising and crawling infants
53% walkers
Majority of school age children

RISK-FACTORS

Underlying bleeding disorders (e.g., von Willebrand disease, platelet disfunction, thrombocytopenia), child abuse/trauma, medications, infections, etc. may all be risk factors leading to bruising in childhood.

GENETICS

Hemophilia is an X-linked disorder affecting males.
von Willebrand disease may be autosomal dominant.
Other platelet disorders have a variety of inheritance patterns.

PATHOPHYSIOLOGY

Extravasation of blood from blood vessels leading to a collection of blood below the surface of the skin

ETIOLOGY

Disorders of blood vessels and surrounding tissue
Platelet abnormalities (function, number)
Coagulation disorders

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